As a result of improvements in multi-functionality of mobile phones, software for the same has grown increasingly complicated and highly sophisticated. As software becomes complicated, the possibility of occurrence of failures (bugs) increases. In order to solve such failures, users must bring their mobile phones to shops or service offices to overwrite correction programs by connecting the mobile phones to an exclusive plug (terminal device), and this is very troublesome.
On the other hand, recently, a method for updating software by acquiring correction programs and additional programs by downloading these from exclusive servers by accessing the exclusive servers via a communication network has been increasingly generalized (For example, refer to Patent Literature 1).
Patent Literature 1: JP-A-2004-134948